[j1elo]

Wait, do you mean that if you write inline PlantUML source such as in your example, an "example-diagram.png" is generated from that code and loaded by the image tag?

That sounds too advanced although I could see an Sphinx doc plugin being able to do that, but not the more basic Markdown viewer in most hosts... so I'll guess that you meant to copy the embedded PlantUML lines to a temp file, and generate a .png, that gets stored together with the .md file.